Requirements

Why do you need a SSD? A normal SD Card is quite limited in lifetime and an SSD is much faster.

Preparation

First, we need the MicroSD to have a bootable Raspbian image written onto it. If you bought a complete bundle you may have gotten a card that is already prepared.
If so, feel free to skip the next steps.
If not, the first step is to create such a card. Please check the official raspberry pi guides for this.

When your SD Card is ready, plug it in along with all of your periphery, and boot the Pi up.
If all went well your screen should show a menu where you can choose to install Raspbian. After the installation, download this script